Fix addons button order for Mac Firefox 3.0-3.6. Reduce duplication.
Fix addons button order for Mac Firefox 3.0-3.6.
Reduce duplication.

Fixes #1149

Ventero/greasemonkey,the8472/greasemonkey,Martii/greasemonkey,the8472/greasemonkey,Martii/greasemonkey,Ventero/greasemonkey,HasClass0/greasemonkey,HasClass0/greasemonkey